A MAP OF LIFE teaches is true: at no stage does she teach all that is contained in the Truth. This development — which we find in theology and nowhere else — combines two things: the work of men’s minds, the over-ruling protection of God. In theology, as in science, progress comes by the minds of men working on what they have been taught: but left to themselves, men may simply make further mistakes. In science they do so. In the teaching of the Church they do not: and the reason is that God intervenes, to prevent the teaching of error by His Church. God’s actions — whedier revelation or sacrament or miracle — are never labour-saving devices: God does not do them to save men the trouble of doing what they can very well do for themselves. In revelation, for instance, God teaches men what they could not (at any rate could not with absolute sureness) find out for themselves : but having given them that. He leaves it to them to meditate upon it and arrive at a clearer understanding of it. He does not do their thinking for them. THE TEACHING CHURCH But if we are to say that in the teaching of the Church there are no mistakes, it is necessary to look a little more closely at what we mean by the phrase “the Teaching Church.” The first teachers in the Church were the apostles : their successors are the bishops. The bishops are the teaching body of the 72